About
AHD VM is a collection of automation scripts and Infrastructure as Code (IaC) used to create a Virtual Machine that fits the requirements to deploy Grain.
We built AHD VM by choosing Open Source Software that fits the following criteria:
- production ready
- optimized for container workloads
- requires the least maintenance possible
Installation
To install AHD VM, follow the installation guide.
Software and Dependencies
AHD VM uses the following software and dependencies:
- Fedora CoreOS - A minimal OS with automatic updates
- k3s - Lightweight Kubernetes
- Helm - The package manager for Kubernetes
The system is armored and does not allow installation of software packages unless included directly in the initial (standard) setup. Therefore, there is no provision for the installation of additional software.
Fedora CoreOS
Fedora CoreOS is the OS used by AHD VM. It's minimal, optimized for container workloads and has automating OS updates to guarantee the best level of security possible.
Auto-Updates and Zincati
Zincati is the tool used for OS auto-updates. If there's any issues with the updates, it's possible to rollback to a previous version of the OS without data loss or corruption.
OS Updates are executed in a configurable maintenance window.
The default maintenance window configured by Smeup LAB is the following (CET timezone)
- Saturday 23:30 to Sunday 00:30
- Sunday 23:30 to Monday 01:00
Memory Swap
Memory Swap is disabled by default on Fedora CoreOS, as recommended by Kubernetes.
SELinux
SELinux is enabled by default.
Firewall
Fedora CoreOS does not have a firewall and all the ports are open by default.
Timezone
Fedora CoreOS highly recommends using UTC.
AHD VM uses UTC.